package com.my.util;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;

//SqlSessionFactory → SqlSession
public class MybatisUtils {

    private static SqlSessionFactory sqlSessionFactory;

    //获取SqlSessionFactory对象
    static {
        try {
            String resource = "mybatis-config.xml";
            InputStream inputStream =  Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    //既然有了 SqlSessionFactory，顾名思义，我们可以从中获得 SqlSession 的实例
    //SqlSession 提供了在数据库执行 SQL 命令所需的所有方法

    public static SqlSession getSqlSession(){
        return sqlSessionFactory.openSession(true);
    }
}
